Chewing it Over

Agriculture in the U.S has become so productive that now we often take it for granted. Chances are, you can enjoy three meals a day at a reasonable price without having to think too long about how to cultivate, raise or process your food. Yet only 1.4% of the US population work directly in farming. How is this possible? Perhaps this topic merits some thought. Is this sustainable? What are some issues and challenges present in farming today?

The Hollowing Out of Midsized Farms

Between 2007 to 2012, most counties in America experienced farm consolidation. With the map below, we can explore which counties have experienced farm consolidation, expansion, partitioning and decline.



The colors in the plot to the left corresponds to the coloring of the counties in the map above. Here, we define farm consolidation (red) to mean that the number of farms decreased in that county while the average farm sizes increased. On the other hand, farm partitioning (blue) means that the number of farms increased while the average farm sizes decreased. Counties where the both farm size and farm number increased we classify as having experienced agricultural land expansion, and counties where both farm size and farm number decreased we classify as having experienced agricultural land decline.


This trend toward farmland consolidation is not limited to between 2007 and 2012. In the last few decades, arguably, the most striking trend in U.S. agriculture is the shift in farm sizes. While the average is about 250 acres and has not changed much, there seems to be a “hollowing out” of the midsized farms, and a shift toward the two extremes. Small farms fluctuate in number, and large farms are growing to monolithic sizes.

Data Source: USDA

Advances in technology has allowed large industrial operations to excel at producing large quantities of one product efficiently, and so large farms can achieve economies of scale more readily. The cost of these technologies has made it very difficult for midsized farms to compete. But at what point is large too large? Have certain regions of the US already hit this point? While this is a very rough graph, the answer is likely, yes, some farm sizes in some regions of the US may already be beyond the point of diminishing returns. Bigger may not always better.

Even if bigger is not always better, can bigger be worse? Do we lose anything by losing midsized farms? Since large farms gain efficiency through monocultures, counties with smaller farms tend to be more diverse than counties with large farms.The loss of small and midsized farms may mean less diversity, but why should diversity matter?

Diversity of commodities

“Diversification” is a strategy for spreading out risk. For example, if, as a farmer, you grew only corn and had a corn rootworm pest outbreak, you run the risk of losing all your crop that year. An extreme example of this is the Irish Potato Famine. If you diversify you reduce the impact that the pest outbreak can have, and thus lower your exposure to risk. So from a risk perspective, a community that produces a diverse medley of products is more resilient to various shocks.

We mapped diversity using the Shannon diversity index and the major contributing products to the agricultural market value of each county.This can be thought of as how uniformly, or how evenly, commodities contribute toward total market value. A high value represents more diversity while a low number suggest a tendency to monoculture. What’s the top commodity produced in your county?

The color of the county corresponds to the dominant commodity (in contribution toward market value). The saturation corresponds to the diversity of commodities in the county. The more saturated the color, the closer the county is to a monoculture. In the map above, we can see a large swath of green that corresponds to the corn belt, and the large brown patch shows the pasturelands. A greyscale version of the map is shown below identifying regions of high and low diversity.

The diversity metric shows how dependent a county is on one product, which has implications for how resilient the community is to price shocks. Low shannon diversity can be thought of as how dependent a county is on one product. To provide some more intuition about the diversity metric, here is an example of two counties on the extreme ends of diversity:

We should be especially concerned about agricultural diversity because the prices of commodities are known to be particularly volatile. This volatility happens because of charcteristics of supply and demand. For certain crops, the supply depends on uncertain factors like weather and pests and the demand for that crop is rather fixed. For example, if the price of onions goes down, you are unlikely to respond by eating more onions. Therefore, an influx of onions on the market will be accompanied by a drastic fall in price.An interesting story of cornering the onion market can be heard here.

So diversification seems like a good strategy, it helps reduce and mitigate risks and provides consumers with more variety. So we would expect communities that are tied to a monoculture and do not spread their risk to be poorly buffered against price shocks. However, from the diversity maps, we can see that counties across the U.S. skew toward monoculture. Why is this?

This is where government payments and insurance play a role.

Government payments

The question is, what is the role of government payments? Should government payments (1) protect farmers against price shocks so that they don’t lose everything if a bad year hits? (2) incentivize farmers to produce enough food so that people don’t go hungry? (3) make sure that farms don’t overtake natural wildlife? The U.S Farm Bill encompasses all three goals. The bill helps codify crop insurance in the U.S and has huge impact on what is grown, produced and eaten.

Government payments and insurance on specific commodities can incentivize large monoculture farms because the risk is no longer borne by the farmer. If the crop fails, the insurance will cover the farmer. This can have a feedback effect where more insurance is needed to protect against instability of monoculture. This is why the Farm Bill can become controversial and divisive. Some consider it “welfare for the well-off” and others highlight its importance to stable food supply. Regardless of the view, we wanted to know who gets the subsidies?

In asking this question, we encountered the paradoxical situation that the largest amount of government payments happen to be going to areas with the highest market value of commodities.

We mapped the data on two metrics: 1) government payments per farms in the county; and 2) government payments per acre of farmland in the county.

The resulting maps tell two different stories. Normalized by number of farms, the region with large farms gets most. On a per acre basis, the spending is highest in the corn-belt, which emphasizes that in America, corn is king - including king of subsides.

Despite these two metrics, some regions gain and loose regardless of the metric. Such as east North Dakota, parts of Louisiana and Arkansa and regions in Arizona.

Aside: What’s going on in Arizona?? In looking at the spending maps, Apache, Navajo and Coconino counties in Arizona all stood out. This region had low subsidies any way you cut it (government spending per acre or government spending per farm). Coincidentally they had high diversity with medium sized farms. They also stood out in their parity in farmer genders with nearly 50% of farm operators being women (much above the national average of 15%; . We were curious why this region was such an outlier. We took some time to investigate what was happening there. Here are some fun findings. The outlier region is Navajo Nation, and like many of the other Indian reservations, it’s quite poor. A look at this map; of US Indian reservations (over 300) was enlightening.

As a sovereign nation, it seems the government did not provide much ag subsidy or the Navajo Nation did not participate in the crop insurance. This seems to have changed more recently in 2016 and got a return in 2018 on insurance they purchased.

What now?

Whether we think about it or not, we support agriculture, directly when we buy groceries or indirectly when we pay taxes, so perhaps every once in a while it’s good to ask: What do we prefer to support:small diverse farms or large efficient farms? This debate about farm size is often posed as “small organic” versus “large industrial,” and each camp touts the advantages of its side: small diverse farms are better buffered against volatility in weather, prices, and pathogens. On the other hand, large industrial operations excel at producing large quantities of one product efficiently, and can achieve economies of scale more readily. Data from the 2017 Agricultural Census is set to be released in early 2019. We’ll be waiting to see whether anything has changed.

In the meantime, at your next meal, ask yourself, does farm size matter?


About the authors

Anjuli Jain Figueroa earned her BS in Civil and Environmental Engineering from University of Michigan, 2009, a MSc. Technology and Policy from MIT, 2012 and is currently working on her PhD in Civil and Environmental Engineering at MIT She studies the coupling of the built and the natural environment, in particular how we manage our natural resources (i.e water and land) and the economic and environmental impacts of different management strategies. Anjuli investigates the tradeoffs between yield, environmental impacts and economic costs of different agricultural management strategies. [website] | [twitter]


Joy Yang graduated with a BA in Statistics from UC Berkeley. She is currently a PhD candidate in Computational and Systems Biology at MIT. Her research focuses on statistical methods for finding the genetic underpinnings for bacteriophage infections. She is broadly interested in methods for analyzing and visualizing large complex datasets. In her spare time, she likes to think about ways of making early statistics education more like fun and games. [website] | [twitter]